Who are the best at world building?

I don't want to derail the "what are you reading now?" thread, but I made a world-building comment there and thought I'd get input from the forum on authors who are particularly good at this. I like reading science fiction and fantasy where authors have put the time in to make the world come alive, so I can also use this discussion to gather recommendations.

Some of the world-building stand-outs that come to mind:

1. Tolkien, of course.

2. Steven Erikson. If you set aside all the linguistics, the Malazan books rival Tolkien in terms of breadth and depth of world creation.

1. Enid Blyton (I am fairly sure she is probably the most prolific world builder could be wrong)
2. Robert Neill (Historical author his ability to describe and warm up a story is amazing)
3. Jonas Islander (and one day he will have a book on my shelves)
4. Shakespeare
5. CS Lewis (not just for Narnia - the Mars Trilogy, The Great Divorce etc)
6. Ellis Peters (Again historical but Cadfael is amazing visually)
7. Kate Morton (more general fiction but she can paint an amazing picture)
8. Steve Cole (Cows in Action it is so funny)
9. Lian Hearne (Tales of the Otori)
10. Pamela Brown (the Finishing School was a Japanese POW very powerful YA Story)
11. JK Rowlling

Austin Tappan Wright, if we're just going off of sheer mass. Easily the most developed world I've ever read, and it certainly even exceeds J.R.R. Tolkien. Best in terms of its ability to serve, interact with, but not get in the way of the story, though? China Miéville.

Although this is not specically by one author but more as whole publishing company (Black Library), I really enjoy the grim-dark worlds of the Warhammer 40,000 Universe. Some of the novels set in there are particularly good. (Gaunt's Ghosts Series, Horus Heresy Series, Night Lords Series)

And Michael Grant's Gone Novels are particuarly good at World Building.

Tolkien fills the sky. GRR Martin doesn't come close at least in part because the further back you go with Tolkien's timeline the more like myth it sounds and feels, whereas Martin's historical references just fade away into a soup of cliche.

I enjoyed His Dark Materials too for the interesting take on an alternate reality.